It looks as if they’re starting to remove some of the lower section of the lower spillway, but it also looks like they’re trying to set up a clean straight cutoff on the upper spillway. This is based on observing the Dam Cam linked above.
A Chico-ER photographer was able to catch the right moment where the plunge pool erosion found a direct pipe inlet opening to a longitudinal drain. If these drains are near the 16 inch diameter estimates that have been tossed about, this is what a "full on" pressurized longitudinal pipe can do.
Pretty impressive flow. Surprised the pipe sections didn't separate from the pressure.
Not a lot of action here, but this is the other camera setup that is located on the high side of the dam at the visitor’s center...
http://www.parks.ca.gov/live/lakeorovillesra